The invention relates to improvements in the construction and operation of pulverizers and, more particularly, to pulverizers of the roll and race configuration wherein compressive force is applied directly to the roller brackets and shear and pivoting means are provided to integrally connect the roller brackets to split corner roller support blocks.
The roll and race type pulverizer configuration is well known. In general, a roll and race type pulverizer includes a stationary housing enclosing a grinding zone, an inlet for introducing the raw coal that is to be pulverized and a horizontally disposed ring positioned in the grinding zone and having an upwardly facing annular grinding surface. A series of circumferentially equally spaced rollers are mounted above the ring which is rotated about an upright axis. Each individual roller is separately supported for rotation about its own axis. A compressive force is directed vertically through the rollers to aid in the grinding process. Air is introduced through a duct at a lower portion of the pulverizer and is utilized to transport the pulverized air-borne coal to a classifier. Coarse material is removed at the classifier and is returned via gravitational force to the grinding zone for further processing. The finer coal particles are transported through the classifier and out of the pulverizer as the finished product.
There have been prior disclosures of various configurations of pulverizers utilizing crushing or grinding rollers for grinding or pulverizing different material. Roller assemblies have been depicted connected to triangular or ring frame loading systems in an attempt to keep the rollers from planetating within the housing. Such frame systems also apply spring pressure through the roller bracket axle system to positively load the rollers against the rotating grinding table and material carried thereon.
Typical disclosures of pulverizers and roller loading systems can be found in U.S. Pat. Nos. 3,061,208 and 3,083,920 wherein a pressure transmitting ring or carrier is used to directly transmit a vertically acting compressive spring force to each pulverizer roller bracket via a pressure transmitting bearing member. In the prior art, each pressure transmitting bearing member carries an equal portion of load transmitted through the pressure frame. In the present invention the spring pressure frame is eliminated and the compressive spring force is transmitted directly to the wheel brackets and split corner roller support blocks. Means are provided to connect adjacent ends of corner blocks and brackets and the connecting means carries only a portion of the compressive spring force, the remainder being transmitted directly to the brackets. The corner blocks, which support the roller system as a unit, additionally support wear plates that contact the pulverizer housing and prevent the roller system for orbiting within the pulverizer.